Apple Books also syncs position in your own epubs, unlike my new Kobo Sage which’ll only sync reading position in books you’ve bought from Kobo. I still love my Kobo Sage and feel like managing my library with Calibre is better than Apple Books. But the iCloud syncing experience with Apple Books is clearly superior. People give Apple a lot of shit for their built in apps not being great (which is a good argument against them having a monopoly on iOS) but at least they nailed Books syncing.